Electronic lottery system and its operating method and computer- readable recording medium in which the electronic lottery program code is stored

ABSTRACT

Using a sealing function the parent system seals the random number x which is generated by a random number generation means, and it, along with both the sealing function and the result calculation function, is made public by a setting publication means. Each of the subsystems (i) which will participate in the lottery sends the random number, which is a response, generated by its random number generation means. The result calculation means of the parent system calculates a lottery result by applying the response ri and the initial value x to the result calculation function, and makes public the lottery result, the initial value x and the response ri. Each of the child subsystems (i) receives this information, and the result verification means determines whether the sealed initial value equals to the value calculated by applying the initial value to the sealing function, and whether the response of each of the child subsystems is recorded, and whether the lottery result equals the value calculated by applying the result calculation function to the initial value x and the response ri.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an electronic lottery systemcomposed of a parent system and a plurality of child subsystems, whichelectronically draw lots.

[0002] Many conventional systems using mechanical methods to draw lotshave previously been proposed, described as follows:

[0003] Laid-open Hei7-131533 (hereafter, referred to as reference 1)shows the “Lottery application reception system”, in which telephonesare utilized in the operation of a lottery in such a way that the parentsystem accepts lottery applications via the push-tone signals oracoustic signals sent by telephone from the child subsystem. Laid-openHei8-101872 (hereafter, referred to as reference 2) shows the “Facilityreservation management system”, in which the parent system accepts thereservation of a facility sent from a terminal in a child subsystem, anddraws lots when reservations conflict, and then notifies the result ofthe lot drawing to the child subsystems.

[0004] Laid-open Hei7-287731 (hereafter, referred to as reference 3)shows the “Network-type card lottery management apparatus and centralcard lottery management method”, in which a central data managementapparatus in the parent system accepts lottery applications usinglottery cards from the terminal data management apparatus in the childsubsystems and then draws lots, and then notifies the results to thechild subsystems.

[0005] Laid-open Sho61-18085 (hereafter, referred to as reference 4)shows the “Public lottery apparatus”, located in the child subsystem,which issues a public lottery ticket with the public lottery number thata person wants.

[0006] Laid-open Hei1-319896 (hereafter, referred to as reference 5)shows the “Electronic cash register with a lottery function”, whichdraws lots by generating a random number when its sum-up key is pushed,and then determines whether this number matches a prize numberpreviously stored in its memory.

[0007] Laid-open Hei5-124305 (hereafter, referred to as reference 6)shows the “Print-out processing method” of increasing a lottery's dramaby hiding the result of an Amitabha-type lottery in such a way that itsuspends the print-out when an Amitabha-type lottery drawing is printedout and then resumes the operation.

[0008] Laid-open Hei6-96109 (hereafter, referred to as reference 7)shows the “game apparatus”, which provides a resultant lottery byelectronically generating an Amitabha-type pattern with several longlines along which include short lines bridged between the long lines,and displaying them, and then selecting one of the long lines accordingto people's requests.

[0009] As described above, there are many conventional proposals forusing mechanical methods to draw lots. However, these methods have theobjective of automating the reception of applications to enter thelottery and then the drawing of lots. Impartiality, which is a mostimportant factor in a lottery, is not sufficiently taken into account.For instance, in references 1 and 2, the parent system draws lots, butdoes so without assuring that the lottery operation is impartiallyperformed. In reference 3, the lottery is performed in accordance with arecorded number on a card; however, this system is vulnerable to unfairacts such as an act of altering the number recorded on the card. The useof the method detailed in reference 4 can prevent the lottery numbersfrom being altered since they are printed on public lottery tickets, butthere is no guarantee of an impartial lottery being made by the parentsystem. In the method detailed in reference 5, the fact that a randomnumber is generated cannot prevent the possibility of unfair acts beingmade because a prize number which has previously been stored in thememory can be altered. In the methods detailed in references 6 and 7,the act of drawing lots is accomplished using an Amitabha-type lotterypattern which is selected by the apparatus. The pattern can be easilyaltered after lottery applications are accepted, thus resulting in aprofitable result for a certain person.

[0010] As described above, using the parent system to determine thelottery result creates the possibility that unfair operations will leadto a specific lottery result being made. When the result of drawing lotsis determined before child subsystems participate, there is thepossibility that one or more of the child subsystems can cheat.

[0011] The objective of the present invention is to provide anelectronic lottery method and system, by which a lottery result isobtained in accordance with random numbers selected by a parent systemand a plurality of child subsystems. None of subsystems can cheat thelottery result. Another objective of the present invention is to providea computer-readable recording medium, on which an electronic lotteryprogram code is recorded, and by which the electronic lottery operationsare performed.

SUMMARY OF THE INVENTION

[0012] One aspect of the present invention involves a first electroniclottery method. In the method, a parent system and a plurality of childsubsystems are both used to operate en electronic lottery. The methodcomprises steps of: generating a random number by the parent system,sealing the random number via a function which makes the sealing processrelatively easy to perform but also makes the seal-breaking process verydifficult to accomplish, and making known the generated random numberfor to child subsystems; generating and sending a random number by eachchild subsystem to the parent system; obtaining a lottery result in theparent system by using a function by which a lottery result iscalculated dependent upon the random number generated by the parentsystem and the random number received from each child subsystem; andmaking public for all the child subsystems by the parent system thelottery result, the random number generated by the parent system, andthe random numbers received from each child subsystem.

[0013] The parent system can use a hash function, such as the MD5 or theRIPE-MD, to seal random numbers and also obtain a lottery result.

[0014] In the first electronic lottery method, a lottery result isobtained by using the random number which is generated in the parentsystem and the random numbers which are generated in the respectivesubsystems. In addition, since the random number generated by the parentsystem has been made public in a sealed manner, none of the childsubsystems can get to know the number when each of them determines itsown response. Also, the parent system cannot change the random numbersin accordance with the responses coming from the child subsystems.Furthermore, since the random numbers generated by the parent system andchild subsystems, as well as the lottery result, are made public,verification can be made. Therefore, an impartial lottery can berealized.

[0015] Another aspect of the present invention involves an electroniclottery system in which the first electronic lottery method is used. Theelectronic lottery system has a parent system and a plurality of childsubsystems. The parent system comprises: random number generation meansfor generating a random number; initial setting means for setting aninitial value by using the random number generated by the random numbergeneration means; initial value sealing means for sealing the initialvalue set by the initial setting means; setting publication means formaking public an initial setting information including the initial valuesealed by the initial value sealing means; response reception means forreceiving a response coming from each of the plurality of childsubsystems; response normalizing means for normalizing the responsereceived by the response reception means; result calculation means forcalculating a lottery result by using the normalized response by theresponse normalizing means and the initial value set by the initialsetting means; and result publication means for making public thelottery result calculated by the result calculating means, the initialvalue set by the initial setting means, and the response received by theresponse reception means; and each of the plurality of child subsystemscomprises: setting reception means for receiving the initial settinginformation made public by the setting publication means of the parentsystem; random number generation means for generating a random number;response generation means for generating a response by using the randomnumber generated by the random number generation means; response sendingmeans for sending the response generated by the response generationmeans; result reception means for receiving the result published by theresult publication means of the parent system; result verification meansfor verifying the result received by the result reception means.

[0016] Yet another aspect of the present invention involves acomputer-readable recording medium, on which an electronic lotteryprogram code is recorded, to realize the first electronic lottery methodand system. The computer-readable recording media for the computer ofthe parent system includes program codes corresponding to the randomnumber generation means, the initial setting means, the initial valuesealing means, the setting publication means, the response receptionmeans, the response normalizing means, the result calculation means, andthe result publication means. The computer-readable recording media forthe computer of each child subsystem includes program codescorresponding to the setting reception means, the random numbergeneration means, the response generation means, the response sendingmeans, the result reception means, and the result verification means.

[0017] Yet another aspect of the present invention involves a secondelectronic lottery method. In the method, a parent system and aplurality of child subsystems are both used to operate en electroniclottery. The method comprises steps of: generating a random number bythe parent system, sealing the random number via a function which makesthe sealing process relatively easy to perform but also makes theseal-breaking process very difficult to accomplish, and making known thegenerated random number to all child subsystems; generating a randomnumber, and then sealing the random number by each child subsystem via afunction which makes the sealing process relatively easy to perform butalso makes the seal-breaking process very difficult to accomplish, andthen sending the random number to the parent system; informing all thechild subsystems by the parent system that the sealed random numberscoming from all of the child subsystems have been received; sending byeach child subsystem the pre-sealed random number to the parent systemafter the child subsystem has been informed; calculating a lotteryresult by the parent system by using a function by which the lotteryresult is calculated dependent upon the random number generated by theparent system and the pre-sealed random number which has been receivedfrom each child subsystem; and making known for each child subsystem bythe parent system the lottery result, the random number generated by theparent system, and the pre-sealed random number received from each childsubsystem.

[0018] The parent system can use a hash function, such as the MD5 or theRIPE-MD, to seal random numbers and also obtain a lottery result. Also,each child subsystem can use the same hash function to seal randomnumbers.

[0019] In the second electronic lottery method, a lottery result isobtained by using the random number which is generated in the parentsystem and the random numbers which are generated in the respectivesubsystems. In addition, since the random number generated by the parentsystem has been made public in a sealed manner, none of the childsubsystems can get to know the number when each of them determines itsown response. Also, the parent system cannot change the random numbersin accordance with the responses coming from the child subsystems. Theparent system, in conjunction with some of the child subsystems, mayleak its own random number, but since the responses of the other childsubsystems are made public in a sealed manner, the parent system is notable to make a special response that is advantageous to any particularchild subsystem. Furthermore, since the random numbers generated by theparent system and child subsystems, as well as the lottery result, aremade public, verification can be made. Therefore, an impartial lotterycan be realized.

[0020] Yet another aspect of the present invention involves anelectronic lottery system using the second electronic lottery method.The electronic lottery system has a parent system and a plurality ofchild subsystems. The parent system comprises: random number generationmeans for generating a random number; initial setting means for settingan initial value by using the random number generated by the randomnumber generation means; initial value sealing means for sealing theinitial value set by the initial setting means; setting publicationmeans for making public an initial setting information including theinitial value sealed by the initial value sealing means; sealed responsereception means for receiving a sealed response coming from each of theplurality of child subsystems; contact-signal publication means formaking public the fact that the sealed response has been received;broken-seal response reception means for receiving a broken-sealresponse coming from each of the plurality of child subsystems, andverifying the received broken-seal response; broken-seal responsenormalizing means for normalizing a broken-seal response verified by thebroken-seal response reception means; result calculation means forcalculating a lottery result by using the broken-seal responsenormalized by the broken-seal response normalizing means and the initialvalue set by the initial setting means; and result publication means formaking public the result including the lottery result calculated by theresult calculation means, the initial value set by the initial settingmeans, and the broken-seal response received by the broken-seal responsereception means; and each of the plurality of child subsystemscomprises: setting reception means for receiving the initial settinginformation which has been made public by the setting publication meansof the parent system; random number generation means for generating arandom number; response generation means for generating a response byusing the random number generated by the random number generation means;response sealing means for sealing the response generated by theresponse generation means; sealed response sending means for sending thesealed response generated by the response sealing means; contact-signalreception means for receiving the sealed response which has been madepublic by the contact-signal publication means of the parent system;contact-signal verification means for verifying the sealed responsereceived by the contact-signal reception means; broken-seal responsesending means for sending the broken-seal response since thecontact-signal verification means can verify the sealed response; resultreception means for receiving the result which has been made public bythe result publication means of the parent system; and resultverification means for verifying the result received by the resultreception means.

[0021] Yet another aspect of the present invention involves acomputer-readable recording medium, on which an electronic lotteryprogram code is recorded, to realize the second electronic lotterymethod and system. The computer-readable recording media for thecomputer of the parent system includes program codes corresponding tothe random number generation means, the initial setting means, theinitial value sealing means, the setting publication means, the sealedresponse reception means, the contact-signal publication means, thebroken-seal response reception means, the broken-seal responsenormalizing means, the result calculation means, and the resultpublication means. The computer-readable recording media for thecomputer of each child subsystem includes program codes corresponding tothe setting reception means, the random number generation means, theresponse generation means, the response sealing means, the sealedresponse sending means, the contact-signal reception means, thecontact-signal verification means, the broken-seal response sendingmeans, the result reception means, and the result verification means.

[0022] Yet another aspect of the present invention involves a thirdelectronic lottery method. In the method, a parent system and a firstand second plurality of child subsystems are all used to operate enelectronic lottery. The method comprises steps of: generating a randomnumber by the parent system, sealing the random number via a functionwhich makes the sealing process relatively easy to perform but alsomakes the seal-breaking process very difficult to accomplish, and makingknown the random number to all child subsystems; generating and sendinga random number to the parent system by each of the first plurality ofchild subsystems, generating and sealing a random number using afunction which makes a sealing process relatively easy to perform butalso makes the seal-breaking process very difficult to accomplish, andsending the number to the parent system by each of the second pluralityof child subsystems, informing all of the second plurality of childsubsystems that the sealed random numbers coming from all of the secondplurality of child subsystems have been received by the parent system;sending by each of the second plurality of child subsystems thepre-sealed random number to the parent system after each of the secondplurality of child subsystems has been informed; obtaining a lotteryresult by the parent system by using a function by which the lotteryresult is calculated dependent upon the random number generated by theparent system, the random numbers received from each of the firstplurality of child subsystems, and the pre-sealed random number whichhas been received from each of the second plurality of child subsystems;and making public for all child subsystems by the parent system thelottery result, the generated random number by the parent system, therandom number received from each of the first plurality of childsubsystems, and the pre-sealed random number which has been receivedfrom each of the second plurality of child subsystems.

[0023] The parent system can use a hash function, such as the MD5 or theRIPE-MD, to seal random numbers and also obtain a lottery result. Also,each child subsystem can use the same hash function to seal randomnumbers.

[0024] In the third electronic lottery method, a lottery result isobtained by using the random number which is generated in the parentsystem and the random numbers which are generated in the respectivesubsystems. In addition, since the random number generated by the parentsystem has been made public in a sealed manner, none of the childsubsystems can get to know the number when each of them determines itsown response. Also, the parent system cannot change the random numbersin accordance with the responses coming from the child subsystems. Theparent system, in conjunction with some of the second plurality of childsubsystems, may leak its own random number, but since the responses ofthe second plurality of child subsystems are made public in a sealedmanner, the parent system is not able to make a special response that isadvantageous to any particular child subsystem. Thus, the second childsubsystems are the key to maintaining security. A child subsystem whichhas concerns about the possibility that other child subsystems, inconjunction with the parent system, might produce an unfair lotteryresult can take part in as the second child subsystem, while anotherchild subsystem which does not have concerns about such a possibilitycan participate in the lottery with such an effort. Thus, an impartialand flexible lottery can be realized.

[0025] Yet another aspect of the present invention involves anelectronic lottery system using the third electronic lottery method. Theelectronic lottery system has a parent system and a first and secondplurality of child subsystems. The parent system comprises: randomnumber generation means for generating a random number; initial settingmeans for setting an initial value by using the random number generatedby the random number generation means; initial value sealing means forsealing a initial value set by the initial setting means; settingpublication means for making public an initial setting informationincluding the initial value sealed by the initial value sealing means;response reception means for receiving a response coming from each ofthe first plurality of child subsystems; sealed response reception meansfor receiving a sealed response coming from each of the second pluralityof child subsystems; contact-signal publication means for making publicthe fact that the response and sealed response have both been received;broken-seal response reception means for receiving a broken-sealresponse coming from each of the second plurality of child subsystems,and verifying the received broken-seal response; broken-seal responsenormalizing means for normalizing the broken-seal response verified bythe broken-seal response reception means; response normalizing means fornormalizing the response received by the response reception means;result calculation means for calculating a lottery result by using thebroken-seal response normalized by the broken-seal response normalizingmeans, the response normalized by the response normalizing means, andthe initial value set by the initial setting means; and resultpublication means for making public a result including the lotteryresult calculated by the result calculation means, the initial value setby the initial setting means, the broken-seal response received by thebroken-seal response reception means, and the response received by theresponse reception means; and each of the first plurality of childsubsystems comprises: setting reception means for receiving the initialsetting information which has been made public by the settingpublication means of the parent system; random number generation meansfor generating a random number; response generation means for generatinga response by using the random number generated by the random numbergeneration means; response sending means for sending the responsegenerated by the response generation means; result reception means forreceiving the result which has been made public by the resultpublication means of the parent system; result verification means forverifying the result received by the result reception means; and each ofthe second plurality of child subsystems comprises: setting receptionmeans for receiving the initial setting information which has madepublic by the setting publication means of the parent system; randomnumber generation means for generating a random number; responsegeneration means for generating a response by using the random numbergenerated by the random number generation means; response sealing meansfor sealing the response generated by the response generation means;sealed response sending means for sending the sealed response generatedby the response sealing means; contact-signal reception means forreceiving the sealed response which has been made public by thecontact-signal publication means of the parent system; contact-signalverification means for verifying the sealed response received by thecontact-signal reception means; broken-seal response sending means forsending the broken-seal response since the contact-signal verificationmeans can verify the sealed response; result reception means forreceiving the result which has been made public by the resultpublication means of the parent system; and result verification meansfor verifying the result received by the result reception means.

[0026] Yet another aspect of the present invention involves acomputer-readable recording medium, on which an electronic lotteryprogram code is recorded, to realize the third electronic lottery methodand system. The computer-readable recording media for the computer ofthe parent system includes program codes corresponding to the randomnumber generation means, the initial setting means, the initial valuesealing means, the setting publication means, the response receptionmeans, the sealed response reception means, the contact-signalpublication means, the broken-seal response reception means, thebroken-seal response normalizing means, the response normalizing means,the result calculation means, and the result publication means. Thecomputer-readable recording media for the computer of each of the firstplurality of child subsystems includes program codes corresponding tothe setting reception means, the random number generation means, theresponse generation means, the response sending means, the resultreception means, and the result verification means. Thecomputer-readable recording media for the computer of each of the secondplurality of child subsystems includes program codes corresponding tothe setting reception means, the random number generation means, theresponse generation means, the response sealing means, the sealedresponse sending means, the contact-signal reception means, thecontact-signal verification means, the broken-seal response sendingmeans, the result reception means, and the result verification means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features and advantages will become apparent from thefollowing description when taken in conjunction with the accompanyingdrawings, in which:

[0028]FIG. 1 shows the entire configuration of a first embodimentaccording to the present invention;

[0029]FIG. 2 shows the configuration of a parent system 101 and childsubsystems 102(i);

[0030]FIG. 3 shows the entire configuration of a second embodimentaccording to the present invention;

[0031]FIG. 4 shows the configuration of a parent system 101 and childsubsystems 103(j),

[0032]FIG. 5 shows the entire configuration of a third embodimentaccording to the present invention; and

[0033]FIG. 6 shows the configuration of a parent system 101 and childsubsystems 102(i) and 103(j).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Referring to the drawings, the details of an embodiment of theinvention will be described.

[0035]FIG. 1 shows the entire configuration of the first embodimentaccording to the present invention. An example of the electronic lotterysystem comprises a parent system 101, several child subsystems 102(i=1˜n), a communication channel (e.g., a data line) 105(i) connecting betweena parent system 101 and several child subsystems 102(i), and anelectronic notice board 100. The parent system 101 and each of the childsubsystems 102(i) comprise recording media P1 and C1, respectively. Therecording media P1 and C1 can be a magnetic disk, semiconductor memoryor other recording media. Further, a communication apparatus with abroadcasting function can be used in place of the electronic noticeboard 100.

[0036]FIG. 2 shows an example configuration of the parent system 101 andthe child subsystems 102(i) in FIG. 1. The lottery program for theparent system which has been recorded in the recording medium P1 in FIG.1 is read into a computer comprising the parent system 101, and thenused to control the operation of the computer to realize the followingoperations: a random number generation means 10, an initial settingmeans 11, an initial value sealing means 12, a setting publication means13, a response reception means 14, a response normalizing means 15, aresult calculation means 16 and a result publication means 17 in theparent system 101. The lottery program for the child subsystems is readinto a computer comprising the child subsystems 102(i), and used tocontrol the operation of the computer to realize the followingoperations: a random number generation means 21, a setting receptionmeans 22, a response generation means 23, a response sending means 24, aresult reception means and a result verifying means 26 in each of thechild subsystems 102.

[0037] In the electronic lottery system of the embodiment, the followingoperation phases are performed to draw lots:

[0038] (1) initial setting phase

[0039] (2) response phase

[0040] (3) result calculation phase

[0041] (4) verification phase

[0042] The operation of each of the phases will be described withreference to FIG. 1 and FIG. 2.

[0043] (1) Initial Setting Phase

[0044] First, in the parent system 101, a random number x is generatedby the random number generation means 10. Then, the initial settingmeans 11 establishes the generated number as the initial value x, and atthe same time determines other things, such as possibly lotteryparticipating child subsystems, the sealing function H which will beused by the subsequent initial value sealing means 12, the resultcalculation function G which will be used by the subsequent resultcalculation means 16, the response method of the child subsystem, andthe normalizing method. Furthermore, things other than the initial valuex are unnecessary to be established each time, when they are alreadydetermined between the parent system 101 and the child subsystems102(i); and their publication is also unnecessary. Next, the initialvalue sealing means 12 seals the initial value as H(x) with the sealingfunction H. Then the setting publication means 13 makes public on theelectronic notice board 100 the sealed initial value H(x), as well asthe other things, which are the names of participating child subsystems,the sealing function H(x), the result calculation function G, theresponse method of the child subsystems and the normalizing method,which are initial setting information.

[0045] (2) Response Phase

[0046] When the setting reception means 22 in each of the childsubsystems 102(i) receives the initial setting information made publicon the electronic notice board, the random number generation means 21generates the random number ri. Next, the response generation means 23generates response data, including the random number ri generated by therandom number generation means 21 in accordance with the response methodof the child subsystem given the made-public initial settinginformation, and then the response sending means 24 sends it to theparent system 101. In addition, a digital signature data can be attachedto the response data, and also be sent by the response sending means 24.

[0047] (3) Result Calculation Phase

[0048] The response reception means 14 in the parent system 101 receivesthe response data including the random number ri from each of the childsubsystems 102(i). When the response reception means 14 receives theresponse data with digital signature data, verification of it is made.Next, the response normalizing means normalizes the received responsedata, extracting no more from response data than the digital signaturedata. Moreover, a prescribed value can be assigned for a child subsystemwhich has not responded within a predetermined period of time. Theresponses from respective child subsystems 102(i) are lined up in aprescribed order, and the arranged responses are named as r. Forinstance, r can be a connection of respective responses r1,r2, . . . inorder. Next, the result calculation means 16 calculates the lotteryresult R(x, r) by substitution of the r and the pre-sealed initial valuex for the corresponding parameters in the result calculation function R.Following that, the result publication means 17 makes public theresponse ri and the pre-sealed initial value x and the lottery resultR(x, r) on the electronic notice board 100.

[0049] (4) Verification Phase

[0050] Each of the child subsystems 102(i) receives the contents madepublic on the electronic notice board 100, which is the lottery resultR(x, r), the pre-sealed initial value x, and the response ri from theresult reception means 25. Then, the result verification means 26verifies the following items to determine whether an impartial lotteryhas been made.

[0051] {circumflex over (1)} that the response ri is describedcorrectly;

[0052] {circumflex over (2)} that the correct H(x) results from thesubstitution of the initial value x for the corresponding parameter inthe sealing function H; and

[0053] {circumflex over (3)} that the correct lottery result R(x, r)results from the substitution of the normalized result r of eachresponse and the initial value x for the lottery result R (x, r).

[0054] A function by which the sealing process can be easily performedbut breaking the seal is very difficult is used as the sealing functionH. The commitment function, one-way function, ciphering function andhash function, such as the MD5 or the RIPE-MD, can all be used for thesealing function H. For the result calculation function G, a function bywhich the lottery result can be calculated according to the x and r isused. The one-way function, decoding function and one-way hash functioncan all be used for the function G. For references on the commonencription technology, “Applied Cryptography”, by Bruce Schneier, JohnWiley & Sons, Inc., 1993 details specific examples of the commitmentfunction, one-way function, encription function and one-way hashfunction.

[0055] According to the electronic lottery system, a lottery resultdependent upon the initial value x set by the random number generationmeans in the parent system 101 and the random (response) number rigenerated by the random number generation means 21 in each of the childsubsystems 102(i) is obtained. Moreover, since the initial value x hasbeen made public in a sealed manner, none of the child subsystems 102(i)can learn the initial value x while deciding its response, and theparent system 101 cannot change the initial value x after it receivesresponses from the child subsystem 102(i). By this manner, an impartiallottery is conducted.

[0056]FIG. 3 shows the entire configuration of the second embodimentaccording to the present invention. An example of the electronic lotterysystem comprises a parent system 101, a plurality of child subsystems103(j) (j=1˜m ), a communication cannel 106(j) (e.g., a datacommunication line) which reliably connects the parent system 101 andthe plurality of the child subsystems 103(j) (j=1˜m ), and an electronicnotice board 100 on which the parent system makes information public.Moreover, the parent system 101 and each of the child subsystems 103(j)comprises recording media P1 and P2 on which the electronic lotteryprogram is recorded. The recording media P1 and P2 can be one of variousrecording media, such as magnetic disk, semiconductor memory or othermedia. Additionally, a communication apparatus with a broadcastingfunction can be used instead of the electronic notice board 100.

[0057]FIG. 4 shows an example configuration of the parent system 101 andthe child subsystem 103(j) of FIG. 3. The lottery program for the parentsystem, which is recorded on the recording medium P2 as shown in FIG. 3,is read into a computer comprising the parent system 101; with it theoperations of the computer are performed. Therewith, the operations ofthe random number generation means 10, the initial setting means 11, theinitial value sealing means 12, the sealed response reception means 31,the contact-signal publication means 32, the seal-breaking responsereception means 33, the broken-seal response normalizing means 35, andthe result calculation means 32 can be performed in the parent system101. The lottery program for the child subsystem which is recorded onthe recording media c2 is read into a computer comprising the childsubsystem 103(j), and with which the operations of the computer areperformed. Therewith, the operations of the setting reception means 41,the random number generation means 42, the response generation means 43,response sealing means 44, the sealed response sending means 45, thecontact-signal reception means 46, the contact-signal verification means47, the broken-seal response sending means 48, the result receptionmeans 49 and the result verification means 40 can be performed in thechild subsystems 103(j).

[0058] The electronic lottery system of the embodiment performs:

[0059] (1) an initial setting phase;

[0060] (2) a response sealing phase;

[0061] (3) a response seal-breaking phase;

[0062] (4) a result calculation phase; and

[0063] (5) a verification phase

[0064] Thereby, the electronic lottery is performed. Next, each of thephases will be described with reference to FIG. 3 and FIG. 4.

[0065] (1) Initial Setting Phase

[0066] The initial setting phase is the same as that of the firstembodiment. Specifically, the random number generation means 10 in theparent system 101 generates the random number x. Then, the initialsetting means 11 determines the initial value x according to thegenerated random number; at the same time all other factors are alsodetermined, such as the child subsystems which will participate in thelottery, the sealing function which will be used by the initial settingmeans 12, the result calculation function G which will be used by thesubsequent result calculation means 36, the response method in the childsubsystem, and the normalizing method. Everything other than the initialvalue x is not needed to be decided each time, if they are decided inadvance between the parent system 101 and the child subsystem 103(j).Neither is its publication. Next, the initial value sealing means 12seals the initial value x into H(x) using the sealing function H. Then,the setting publication means 13 makes public on the electronic noticeboard 100 the sealed initial value H(x) as well as the other factors,such as the subsystems that are participating, the sealing function H,the result calculation function H, the response method in the childsubsystem, and the normalizing method.

[0067] (2) Response Sealing Phase

[0068] When the setting reception means 41 in each of the childsubsystems 103(j) receives the initial setting information which is madepublic on the electronic notice board 100, the random number generationmeans 42 generates a random number yj. Next, the response generationmeans 43 generates response data including the generated random numberyj in accordance with the response method in the child subsystem asdescribed in the made-public initial setting information. Then, theresponse sealing means 44 seals the response data including yj intoH(yj) using the sealing function H in the made-public initial settinginformation, and the sealed response sending means 45 sends the sealedresponse H(yj) to the parent system 101. In the sealed response sendingmeans 45, a digital signature of the child subsystem 103(j),corresponding to the sealed response H(yj) can be attached to the sealedresponse H (yj). In the embodiment, the sealing function H is the sameas that used by the initial value sealing means 12 in the parent system101, but another sealing function can also be used instead.

[0069] (3) Response Seal-breaking Reception Phase

[0070] The sealed response reception means 31 in the parent system 101receives the sealed responses H(yj) from each of the child subsystems103(j). At this time, the digital signature, if attached, is verified.When the sealed responses H(yj) arrive from all child subsystems 103(j),the contact-signal publication means 32 makes public on the electronicnotice board 100 the sealed responses H(yj) received from the childsubsystem 103(j).

[0071] When the contact-signal reception means 46 in each of childsubsystems 103(j) receives the aforementioned contact signal H(yj) fromthe electronic notice board 100, it forwards the signal to thecontact-signal verification means 47. The contact-signal verificationmeans 47 determines whether all contact signals of child subsystems103(j), or all sealed responses H(yj) are received, and also determineswhether its own sealed responses have been noted correctly. If they aredetermined to be correct, the broken-seal response sending means sendsthe pre-sealed response yj (i.e., the response that the responsegeneration means has made), which is as a broken-seal response, to theparent system 101. Further, in the broken-seal response sending means48, a digital signature of the child subsystem 103(j) corresponding tothe broken-seal response yj can be attached to the broken-seal responseyj.

[0072] (4) Result Calculation Phase

[0073] The broken-seal response reception means 33 in the parent system101 receives the broken-seal response yj from each of the childsubsystems 103(j). Then, the digital signature, if attached, isverified. Next, it is determined whether the broken-seal response yjreliably corresponds to the sealed response H(yj) by substituting thebroken-seal response for the corresponding parameter in the sealingfunction H, and then comparing the resultant value to the sealedresponse H(yj).

[0074] Next, the broken-seal response normalizing means 35 normalizesthe broken-seal response yj from each of the child subsystems 103(j).Only the response without the digital signature(if attached) is taken.Then, the sealed responses from the respective child subsystems 103(j)are lined up in a predetermined order, wherein the arranged bit patternis named as y. The y can be a connection of respective broken-sealresponses in a predetermined order such as y1, y2, . . . Next, theresult calculation means 36 calculates the lottery result R(x, y ) insuch a way that the y and the pre-sealed initial value x are bothsubstituted for the corresponding parameters in the result calculationfunction R. Then, the result publication means 37 makes public on theelectronic notice board each broken-seal response yj from each childsubsystem 103(j) and the pre-sealed initial value x and the lotteryresult R(x, y).

[0075] (5) Verification Phase

[0076] The result reception means 49 in each of the child subsystems103(j) receives the contents made publish on the electronic notice board100, namely, the lottery result R(x, y ), the pre-sealed initial value xand the broken-seal response yj of each child subsystem 103(j), and thendetermines the following items to verify whether or not an impartiallottery has taken place.

[0077] {circumflex over (1)} whether its own broken-seal response yj isdescribed correctly;

[0078] {circumflex over (2)} whether the resultant value fromsubstituting the initial value x for the corresponding parameter of thesealed function H equals H(x);

[0079] {circumflex over (3)} whether the resultant value fromsubstituting the broken-seal response yj for the corresponding parameterin the sealing function H equals H(yj); and

[0080] {circumflex over (4)} whether the resultant value fromsubstituting each broken-seal response normalizing result y and theinitial value x for the corresponding parameters in the resultcalculation function R, equals the lottery result R(x, y).

[0081] The hash function, such as the MD5 or the RIPE-MD, as well as thecommitment function, one-way function, or ciphering function can be usedfor the sealing function H in the same manner as in the firstembodiment. Moreover, the one-way function, the decoding function, orthe one-way hash function can be used for the result calculationfunction G.

[0082] According to the aforementioned electronic lottery system, theinitial value x is generated by the random number generation means 10 inthe parent system 101 and the lottery result is dependent upon therandom (response) number yj generated by the random number generationmeans 42. Since the initial value x is made public in advance in asealed manner, the child subsystems 103(j) do not need to know theinitial value x in order to determine its own responses. Accordingly,the parent system 101 cannot change the initial value x after receivingresponses from the child subsystems 103(j). The parent system 101, inconjunction with some of the child subsystems 103(j), may leak theinitial value x, but since the responses of the other child subsystemsare made public in a sealed manner, the parent system 101 is not able tomake a special response that is advantageous to any particular childsubsystem 103(j). Therefore, an impartial lottery is realized.

[0083]FIG. 5 shows the entire configuration of the third embodimentaccording to the present invention. The example of the electroniclottery system comprises a parent system 101, several child subsystems102(i) (i=1˜n ), child subsystems 103(j) (j=1˜m ), reliablecommunication channels 105(i) and 106(j) (e.g., a data communicationline) which connects the parent system 101 with several child subsystems102(i) and 103(j), and an electronic notice board 100 on which theparent system 101 can make information public. Moreover, the parentsystem 101 and each of the child subsystems 102(i) and 103(j) comprisesrecording media P3 and C3 and C4, respectively, on each of which anelectronic lottery program is recorded. The recording media P3, C3 andC4 can be magnetic disk, semiconductor memory or other recording media.A communication apparatus with a broadcasting function can be usedinstead of the electronic notice board 100.

[0084]FIG. 6 shows an example configuration of a parent system 101,child subsystems 102(i) and the child subsystems 103(j) from FIG. 5. Thelottery program for the parent system, recorded on the recording mediumP3 from FIG. 5, is read into a computer comprising the parent system101; with it the operation of the computer is performed. Specifically,the operations of a random number generation means 10, an initialsetting means 11, an initial value sealing means 12, an settingpublication means 13, a sealed response reception means 51, a responsereception means 52, a contact-signal publication means 53, a broken-sealresponse reception means 54, a broken-seal response normalizing means55, a response normalizing means 56, a result calculation means 57 and aresult publication means 58 are performed by the parent system 101.Moreover, the lottery program for the child subsystems which has beenrecorded on each of the recording media C3, as shown in FIG. 5, is readinto a computer comprising child subsystems 102(i); with it theoperation of the computer is performed. Specifically, the operations ofa random number generation means 21, a setting reception means 22, areception generation means 23, response sending means 24, acontact-signal reception means 60, a contact-signal confirmation means61, a result sending means 62, and a result verification means 63 ineach of the child subsystems 102(i) are realized. Furthermore, thelottery program for the child subsystems recorded on each of therecording media C4, as shown in FIG. 5, is read into a computercomprising the child subsystems 103(j); with it the operation of thecomputer is performed. Specifically, the operations of a settingreception means 41, a random number generation means 42, a responsegeneration means 43, a response sealing means 44, a sealed responsesending means 45, a contact-signal reception means 70, a contact-signalverification means 71, a broken-seal response sending means 72, a resultreception means 73, and a result verification means 74 in each of thechild subsystems 103(j) are realized.

[0085] In the electronic lottery system of the embodiment, theelectronic lottery operations are performed. The operations comprise:

[0086] (1) an initial setting phase;

[0087] (2) a response phase;

[0088] (3) a sealed response phase;

[0089] (4) a response seal-breaking phase;

[0090] (5) a result calculation phase; and

[0091] (6) a verification phase

[0092] Each of these phases will be described below with reference toFIGS. 5 and 6.

[0093] (1) Initial Setting Phase

[0094] The initial setting phase is the same as that of the firstembodiment. In other words, the random number generation means in theparent system 101 generates a random number x, and then the initialsetting means 11 establishes the generated random number as the randomnumber x, and at the same time determines additional factors, such aswhich of the child subsystems will participate in the lottery, thesealing function H which will be used by the initial value sealing means12, the result calculation function G which will be used by thesubsequent result calculation means 57, the response method of the childsubsystems, and the normalizing method. Only the initial value x must tobe determined each time, if other factors have already been determinedbetween the parent system 101 and the child subsystems 102(i) and103(j). Its publication is unnecessary. Next, the initial value sealingmeans 12 seals the initial value x using the sealing function H intoH(x), and then the setting publication means 13 makes public on theelectronic notice board 100 the sealed initial value H(x) and the otherfactors such as which the child subsystems will participate in, thesealing function H, the result calculation function G, the responsemethod of the child subsystems and the normalizing method as initialsetting information.

[0095] (2) Response Phase

[0096] The operation in the response phase is performed by each of thechild subsystems 102(i). The content of the operation is the same asthat of the first embodiment. Specifically, when the setting receptionmeans 22 in each of the child subsystems 102(i) receives from theelectronic notice board 100 the made-public initial setting information,the random generation means 21 generates a random number ri. Followingthat, the response generation means 23 generates response data includingthe generated random number by the random generation means 21. Then, theresponse sending means 24 sends it to the parent system 101.Furthermore, the response sending means can send the digital signatureof the child subsystem 102(i) corresponding to the response ri alongwith the ri.

[0097] (3) Response Sealing Phase

[0098] The operation of the response sealing phase is performed in eachof the child subsystems 103 (i). Its content is the same as that of thesecond embodiment. When the setting reception means 41 in each of thechild subsystems 103(j) receives from the electronic notice board 100they made public the initial setting information, the random numbergeneration means 42 generates a random number yj. Next, the responsegeneration means 43 generates response data including the generatedrandom number yj in accordance with the response method in the childsubsystem described in the made-public initial setting information.Then, the response sealing means 44 seals the response data yj using thesealing function H described in the made-public initial settinginformation into H(yj), and the sealed response sending means 45 sendsthe sealed response H(yj) to the parent system 101. Further, the sealedresponse sending means 45 can send a digital signature of the childsubsystem 103(j), corresponding to the sealed response H(yj) along withthe sealed response H(yj).

[0099] (4) Response Seal-breaking Phase

[0100] The sealed response reception means 51 in the parent system 101receives the sealed response H(yj) from each of the child subsystems103(j). The digital signature, if attached, is verified. The sealedresponse reception means 52 receives the response ri from each of thechild subsystems 102(i). The digital signature, if attached, isverified. When the sealed responses H(yj) arrive from all the childsubsystems 103(j) and the responses ri arrive from all the childsubsystems 102(i), the contact-signal publication means 32 makes publicon the electronic notice board 100 the sealed responses H(yj) fromrespective child subsystems 103(j) and the ri from respective childsubsystems 102(i) as a contact signal.

[0101] When the contact-signal reception means 70 in each of childsubsystems 103(j) receives the aforementioned contact signal from theelectronic notice board 100, it forwards the signal to thecontact-signal verification means 71. The contact-signal verificationmeans 71 determines whether all contact signals of child subsystems103(j), or all sealed responses H(yj) and the response ri of each of thechild subsystems 102(i) are obtained, and also determines whether itsown sealed responses have been noted correctly. If they are verified,the broken-seal response sending means sends the pre-sealed response yj(i.e., the response that the response generation means has made), whichis as a broken-seal response, to the parent system 101. In thebroken-seal response sending means 48, a digital signature of the childsubsystem 103(j) corresponding to the broken-seal response yj can beattached to the broken-seal response yj.

[0102] The contact-signal reception means 60 in each of the childsubsystems 102(i) receives the contact-signal made public on theelectronic notice board 100, determining whether the sealed responses ofthe respective child subsystems 103(j) and the responses of therespective subsystems 102(i) have been prepared, as well as whether itsown response has been noted correctly.

[0103] (5) Result Calculation Phase

[0104] The broken-seal response reception means of the parent system 101receives the broken-seal response yj from each of the child subsystems103(j). The digital signature in the received response, if attached, isverified. Whether the broken-seal response yj corresponds to the sealedresponse H(j) correctly is determined by substituting the sealedresponse for the corresponding parameter in the sealing function H, andthen comparing the result with the sealed response H(yj).

[0105] Next, the broken-seal response normalizing means 55 normalizesthe sealed response yj from each of the child subsystems 103(j). Whenthe sealed response includes the digital signature, only the responsewithout the digital signature is taken. Moreover, the sealed responsesfrom respective child subsystems 103(j) are lined up wherein thebit-pattern of the arranged responses is named as y. For example, y canbe a connection of respective sealed responses in a predetermined order,such as y1, y2, . . . .

[0106] Next, the response normalizing means 56 normalizes each responseri from each of the child subsystems 102(i). For example, when theresponse includes the digital signature, only the response without thesignature is taken, or a prescribed value is assigned to the childsubsystem which has not responded within a predetermined period of time.Moreover, the bit-pattern of the lined-up responses from respectivechild subsystems 102(i) is named as r. For example, the r can be aconnection of respective responses in a predetermined order, such as r1,r2, . . . .

[0107] Next, the result calculation means 57 calculates the lotteryresult R(x, y, r) by substituting the y and r and the pre-sealed initialvalue x for the corresponding parameters in the result calculationfunction R. Next, the result publication means 58 makes public on theelectronic notice board 100 the sealed response yj from each of thesubsystems 103(j), the response ri from each of the child subsystems102(i), the pre-sealed initial value x and the lottery result R(x, y,r).

[0108] (6) Verification Phase

[0109] The result reception in each of the child subsystems 103(j)receives the contents made public on the electronic notice board 100, orthe lottery result R(x, y, r), the pre-sealed initial value x, thebroken-seal response yj of each of the child subsystems 103(j) and theresponse of each of the child subsystems 102(i), and then the resultverification means 74 determines whether the following items occurred inorder to verify if an impartial lottery has occurred.

[0110] {circumflex over (1)} whether its own broken-seal response yjhave been noted correctly;

[0111] {circumflex over (2)} whether the resultant value fromsubstituting the initial value x for the corresponding parameter of thesealed function H, equals H(x);

[0112] {circumflex over (3)} whether the resultant value of substitutingthe broken-seal response yj for the corresponding parameter in thesealing function H, equals H(yj); and

[0113] {circumflex over (4)} whether the result value of substitutingeach broken-seal response yj normalizing result y, each response rinormalizing result r and the initial value x, for the correspondingparameters in the result calculation function R, equals the lotteryresult R(x, y, r).

[0114] The result reception means 62 in each of the child subsystems102(i) receives the contents made public on the electronic notice board100, and then the result verification means 63 determines whether thefollowing items occurred in order to verify if an impartial lottery hasoccurred.

[0115] {circumflex over (1)} whether its own response yj have been notedcorrectly;

[0116] {circumflex over (2)} whether the resultant value fromsubstituting the initial value x for the corresponding parameter of thesealing function H, equals H(x);

[0117] {circumflex over (3)} whether the resultant value fromsubstituting the broken-seal response yj of each of child subsystems103(j) for the corresponding parameter in the sealing function H, equalsH(yj);

[0118] {circumflex over (4)} whether the resultant value fromsubstituting each broken-seal response yj normalizing result y, eachresponse ri normalizing result r and the initial value x for thecorresponding parameters in the result calculation function R, equalsthe lottery result R(x, y, r).

[0119] The hash function, such as the MD5 or the RIPE-MD, as well as thecommitment function, one-way function, or ciphering function can all beused for the sealing function H in the same manner as in the first andsecond embodiment. Moreover, the one-way function, the decodingfunction, or the one-way hash function can be used for the resultcalculation function G.

[0120] According to the aforementioned electronic lottery system, thelottery result is dependent upon the initial value x which is set by therandom number generation means 10 in the parent system 101, the random(response) number ri generated by the random number generation means 21in each of the child subsystems 102(i) and the random (response) numberri generated by the random number generation means 42 in each of thechild subsystems 103(j). Since the initial value x has been made publicin a sealed manner, none of the child subsystems 102(i) or 103(j) canget to know the initial value x as they decide their own response, whilethe parent system 101 cannot change the initial value x after it hasreceived responses from the child subsystems. The parent system 101, inconjunction with some of the child subsystems, may leak the initialvalue x, but since the responses of the other child subsystems 103(j)are made public in a sealed manner, specially advantageous responsescannot be made if not in conjunction with all the child subsystems103(j).

[0121] Thus, the child subsystems 103(j) of the third embodiment are thekey to maintaining security. A child subsystem which has concerns aboutthe possibility that other child subsystems, in conjunction with theparent system, might produce an unfair lottery result can take part inthe procedure by acting as a child subsystem 103(j); on the other hand,a child subsystem which does not have concerns about such a possibilitycan participate in the lottery with less effort. Therefore, an impartiallottery can be realized.

[0122] According to the aforementioned invention, the following resultcan be obtained.

[0123] An impartial lottery result can be accomplished independent ofthe initial value randomly generated by the parent system and theresponses generated by each of child subsystems.

[0124] Moreover, according to the second electronic lottery method andthe electronic lottery system using it and a recording medium, uponwhich a computer-readable electronic lottery program is recorded, eventhough a parent system, in conjunction with some of the childsubsystems, leaks the initial value, an advantageous responses for saidsame cannot be made, since the responses of the other subsystems havebeen made public in a sealed manner. Thus, or a more impartial lotterycan be realized.

[0125] According to the third electronic lottery method and theelectronic lottery system using it and a recording medium upon which acomputer-readable electronic lottery program is recorded, since thesecond child subsystems are the key to maintaining security, a childsubsystem which has concerns about the possibility that other childsubsystems, in conjunction with the parent system, might produce anunfair lottery result can take part in as the second child subsystem,while another child subsystem which does not have concerns about such apossibility can participate in the lottery with such an effort. Thus, animpartial and flexible lottery can be realized.

What is claimed is:
 1. An electronic lottery method using a parentsystem and a plurality of child subsystems, comprising steps of:generating a random number by the parent system, sealing the randomnumber via a function which makes the sealing process relatively easy toperform but also makes the seal-breaking process very difficult toaccomplish, and making known the generated random number for to childsubsystems; generating and sending a random number by each childsubsystem to the parent system; obtaining a lottery result in the parentsystem by using a function by which a lottery result is calculateddependent upon the random number generated by the parent system and therandom number received from each child subsystem; and making public forall the child subsystems by the parent system the lottery result, therandom number generated by the parent system, and the random numbersreceived from each child subsystem.
 2. An electronic lottery methodusing a parent system and a plurality of child subsystems, comprisingsteps of: generating a random number by the parent system, sealing therandom number via a function which makes the sealing process relativelyeasy to perform but also makes the seal-breaking process very difficultto accomplish, and making known the generated random number to all childsubsystems; generating a random number, and then sealing the randomnumber by each child subsystem via a function which makes the sealingprocess relatively easy to perform but also makes the seal-breakingprocess very difficult to accomplish, and then sending the random numberto the parent system; informing all the child subsystems by the parentsystem that the sealed random numbers coming from all of the childsubsystems have been received; sending by each child subsystem thepre-sealed random number to the parent system after the child subsystemhas been informed; calculating a lottery result by the parent system byusing a function by which the lottery result is calculated dependentupon the random number generated by the parent system and the pre-sealedrandom number which has been received from each child subsystem; andmaking known for each child subsystem by the parent system the lotteryresult, the random number generated by the parent system, and thepre-sealed random number received from each child subsystem.
 3. Anelectronic lottery method using a parent system and a first and secondplurality of child subsystems, comprising steps of: generating a randomnumber by the parent system, sealing the random number via a functionwhich makes the sealing process relatively easy to perform but alsomakes the seal-breaking process very difficult to accomplish, and makingknown the random number to all child subsystems; generating and sendinga random number to the parent system by each of the first plurality ofchild subsystems, generating and sealing a random number using afunction which makes a sealing process relatively easy to perform butalso makes the seal-breaking process very difficult to accomplish, andsending the number to the parent system by each of the second pluralityof child subsystems, informing all of the second plurality of childsubsystems that the sealed random numbers coming from all of the secondplurality of child subsystems have been received by the parent system;sending by each of the second plurality of child subsystems thepre-sealed random number to the parent system after each of the secondplurality of child subsystems has been informed; obtaining a lotteryresult by the parent system by using a function by which the lotteryresult is calculated dependent upon the random number generated by theparent system, the random numbers received from each of the firstplurality of child subsystems, and the pre-sealed random number whichhas been received from each of the second plurality of child subsystems;and making public for all child subsystems by the parent system thelottery result, the generated random number by the parent system, therandom number received from each of the first plurality of childsubsystems, and the pre-sealed random number which has been receivedfrom each of the second plurality of child subsystems.
 4. The electroniclottery method according to one of claims 1, 2 and 3, wherein the parentsystem uses a hash function to seal random numbers.
 5. The electroniclottery method according to one of claims 2, 3 and 4, wherein each ofchild subsystems uses a hash function to seal random numbers.
 6. Anelectronic lottery system having a parent system and a plurality ofchild subsystems, wherein the parent system comprises: random numbergeneration means for generating a random number; initial setting meansfor setting an initial value by using the random number generated by therandom number generation means; initial value sealing means for sealingthe initial value set by the initial setting means; setting publicationmeans for making public an initial setting information including theinitial value sealed by the initial value sealing means; responsereception means for receiving a response coming from each of theplurality of child subsystems; response normalizing means fornormalizing the response received by the response reception means;result calculation means for calculating a lottery result by using thenormalized response by the response normalizing means and the initialvalue set by the initial setting means; and result publication means formaking public the lottery result calculated by the result calculatingmeans, the initial value set by the initial setting means, and theresponse received by the response reception means; and each of theplurality of child subsystems comprises: setting reception means forreceiving the initial setting information made public by the settingpublication means of the parent system; random number generation meansfor generating a random number; response generation means for generatinga response by using the random number generated by the random numbergeneration means; response sending means for sending the responsegenerated by the response generation means; result reception means forreceiving the result published by the result publication means of theparent system; result verification means for verifying the resultreceived by the result reception means.
 7. An electronic lottery systemhaving a parent system and a plurality of child subsystems, wherein theparent system comprises: random number generation means for generating arandom number; initial setting means for setting an initial value byusing the random number generated by the random number generation means;initial value sealing means for sealing the initial value set by theinitial setting means; setting publication means for making public aninitial setting information including the initial value sealed by theinitial value sealing means; sealed response reception means forreceiving a sealed response coming from each of the plurality of childsubsystems; contact-signal publication means for making public the factthat the sealed response has been received; broken-seal responsereception means for receiving a broken-seal response coming from each ofthe plurality of child subsystems, and verifying the receivedbroken-seal response; broken-seal response normalizing means fornormalizing a broken-seal response verified by the broken-seal responsereception means; result calculation means for calculating a lotteryresult by using the broken-seal response normalized by the broken-sealresponse normalizing means and the initial value set by the initialsetting means; and result publication means for making public the resultincluding the lottery result calculated by the result calculation means,the initial value set by the initial setting means, and the broken-sealresponse received by the broken-seal response reception means; and eachof the plurality of child subsystems comprises: setting reception meansfor receiving the initial setting information which has been made publicby the setting publication means of the parent system; random numbergeneration means for generating a random number; response generationmeans for generating a response by using the random number generated bythe random number generation means; response sealing means for sealingthe response generated by the response generation means; sealed responsesending means for sending the sealed response generated by the responsesealing means; contact-signal reception means for receiving the sealedresponse which has been made public by the contact-signal publicationmeans of the parent system; contact-signal verification means forverifying the sealed response received by the contact-signal receptionmeans; broken-seal response sending means for sending the broken-sealresponse since the contact-signal verification means can verify thesealed response; result reception means for receiving the result whichhas been made public by the result publication means of the parentsystem; and result verification means for verifying the result receivedby the result reception means.
 8. An electronic lottery system having aparent system and a first and second plurality of child subsystems,wherein the parent system comprises: random number generation means forgenerating a random number; initial setting means for setting an initialvalue by using the random number generated by the random numbergeneration means; initial value sealing means for sealing a initialvalue set by the initial setting means; setting publication means formaking public an initial setting information including the initial valuesealed by the initial value sealing means; response reception means forreceiving a response coming from each of the first plurality of childsubsystems; sealed response reception means for receiving a sealedresponse coming from each of the second plurality of child subsystems;contact-signal publication means for making public the fact that theresponse and sealed response have both been received; broken-sealresponse reception means for receiving a broken-seal response comingfrom each of the second plurality of child subsystems, and verifying thereceived broken-seal response; broken-seal response normalizing meansfor normalizing the broken-seal response verified by the broken-sealresponse reception means; response normalizing means for normalizing theresponse received by the response reception means; result calculationmeans for calculating a lottery result by using the broken-seal responsenormalized by the broken-seal response normalizing means, the responsenormalized by the response normalizing means, and the initial value setby the initial setting means; and result publication means for makingpublic a result including the lottery result calculated by the resultcalculation means, the initial value set by the initial setting means,the broken-seal response received by the broken-seal response receptionmeans, and the response received by the response reception means; andeach of the first plurality of child subsystems comprises: settingreception means for receiving the initial setting information which hasbeen made public by the setting publication means of the parent system;random number generation means for generating a random number; responsegeneration means for generating a response by using the random numbergenerated by the random number generation means; response sending meansfor sending the response generated by the response generation means;result reception means for receiving the result which has been madepublic by the result publication means of the parent system; resultverification means for verifying the result received by the resultreception means; and each of the second plurality of child subsystemscomprises: setting reception means for receiving the initial settinginformation which has made public by the setting publication means ofthe parent system; random number generation means for generating arandom number; response generation means for generating a response byusing the random number generated by the random number generation means;response sealing means for sealing the response generated by theresponse generation means; sealed response sending means for sending thesealed response generated by the response sealing means; contact-signalreception means for receiving the sealed response which has been madepublic by the contact-signal publication means of the parent system;contact-signal verification means for verifying the sealed responsereceived by the contact-signal reception means; broken-seal responsesending means for sending the broken-seal response since thecontact-signal verification means can verify the sealed response; resultreception means for receiving the result which has been made public bythe result publication means of the parent system; and resultverification means for verifying the result received by the resultreception means.
 9. The electronic lottery method according to one ofclaims 6, 7 and 8, wherein the initial value sealing means of the parentsystem uses a hash function to seal an initial value.
 10. The electroniclottery method according to one of claims 6, 7, 8 and 9, wherein theresult calculation means of the parent system uses a hash function toobtain a lottery result.
 11. The electronic lottery method according toone of claims 6, 7, 8, 9 and 10, wherein the response sealing means ofeach of child subsystems uses a hash function to seal a response. 12.The electronic lottery method according to one of claims 6, 7 and 8,wherein the response normalizing means of the parent system uses aprescribed value for a response of each of the child subsystems whichhas not responded within a designated time period.
 13. A computer usablemedium with a computer readable program code means embodied therein,which corresponds to the computer processes of an electronic lotterysystem which has a parent system and a plurality of child subsystems,wherein the computer processes that are performed by the computer of theparent system comprises: a random number generation process forgenerating a random number; an initial setting process for setting aninitial value by using the random number generated by the random numbergeneration process; an initial value sealing process for sealing theinitial value set by the initial setting process; a setting publicationprocess for making public an initial setting information including theinitial value sealed by the initial value sealing process; a responsereception process for receiving a response coming from each of theplurality of child subsystems; a response normalizing process fornormalizing the response received by the response reception process; aresult calculation process for calculating a lottery result by using theresponse normalized by the response normalizing process and the initialvalue set by the initial setting process; and a result publicationprocess for making public the lottery result calculated by the resultcalculation process, the initial value set by the initial settingprocess, and the response received by the response reception process;and the computer processes, that are performed by the computer of eachof the child subsystems, comprises: a setting reception process forreceiving the initial setting information which has been made public bythe setting publication process; a random number generation process forgenerating a random number; a response generation process for generatinga response by using the random number generated by the random numbergeneration process; a response sending process for sending the responsegenerated by the response generation process; a result reception processfor receiving the result which has been made public by the resultpublication process of the parent system; a result verification processfor verifying the result received by the result reception process.
 14. Acomputer usable medium with a computer readable program code meansembodied therein, which corresponds to the computer processes of anelectronic lottery system which has a parent system and a plurality ofchild subsystems, wherein the computer processes that are performed bythe computer of the parent system comprises: a random number generationprocess for generating a random number; an initial setting process forsetting an initial value by using the random number generated by therandom number generation process; an initial value sealing process forsealing the initial value set by the initial setting process; a settingpublication process for making public an initial setting informationincluding the initial value sealed by the initial value sealing process;a sealed response reception process for receiving a sealed responsecoming from each of the plurality of child subsystems; a contact-signalpublication process for making public the fact that the sealed responsehas been received; a broken-seal response reception process forreceiving a broken-seal response coming from each of the plurality ofchild subsystems, and verifying the received broken-seal response; abroken-seal response normalizing process for normalizing a broken-sealresponse verified by the broken-seal response reception process; aresult calculation process for calculating a lottery result by using thebroken-seal response normalized by the broken-seal response normalizingprocess and the initial value set by the initial setting process; and aresult publication process for making public the result including thelottery result calculated by the result calculation process, the initialvalue set by the initial setting process, and the broken-seal responsereceived by the broken-seal response reception process; and the computerprocesses, that are performed by the computer of each of the pluralityof child subsystems, comprises: a setting reception process forreceiving the initial setting information which has been made public bythe setting publication process of the parent system; a random numbergeneration process for generating a random number; a response generationprocess for generating a response by using the random number generatedby the random number generation process; a response sealing process forsealing the response generated by the response generation process; asealed response sending process for sending the sealed responsegenerated by the response sealing process; a contact-signal receptionprocess for receiving the sealed response which has been made public bythe contact-signal publication process of the parent system; acontact-signal verification process for verifying the sealed responsereceived by the contact-signal reception process; a broken-seal responsesending process for sending the broken-seal response since thecontact-signal verification process can verify the sealed response; aresult reception process for receiving the result which has been madepublic by the result publication process of the parent system; and aresult verification process for verifying the result received by theresult reception process.
 15. A computer usable medium with a computerreadable program code means embodied therein, which corresponds to thecomputer processes of an electronic lottery system which has a parentsystem and a first and second plurality of child subsystems, wherein thecomputer processes that are performed by the computer of the parentsystem comprises: a random number generation process for generating arandom number; an initial setting process for setting an initial valueby using the random number generated by the random number generationprocess; an initial value sealing process for sealing the initial valueset by the initial setting process; a setting publication process formaking public an initial setting information including the initial valuesealed by the initial value sealing process; a response receptionprocess for receiving a response coming from each of the first pluralityof child subsystems; a sealed response reception process for receiving asealed response coming from each of the second plurality of childsubsystems; a contact-signal publication process for making public thefact that the response and sealed response have both been received; abroken-seal response reception process for receiving a broken-sealresponse coming from each of the second plurality of child subsystems,and verifying the received broken-seal response; a broken-seal responsenormalizing process for normalizing the broken-seal response verified bythe broken-seal response reception process; a response normalizingprocess for normalizing the response received by the response receptionprocess; a result calculation process for calculating a lottery resultby using the broken-seal response normalized by the broken-seal responsenormalizing process, the response normalized by the response normalizingprocess and the initial value set by the initial setting process; and aresult publication process for making public a result including thelottery result calculated by the result calculation process, the initialvalue set by the initial setting process, the broken-seal responsereceived by the broken-seal response reception process, and the responsereceived by the response reception process; and the computer processesthat are performed by the computer of each of the first plurality ofsubsystems comprises: a setting reception process for receiving theinitial setting information which has been made public by the settingpublication process of the parent system; a random number generationprocess for generating a random number; a response generation processfor generating a response by using the random number generated by therandom number generation process; a response sending process for sendingthe response generated by the response generation process; a resultreception process for receiving the result which has been made public bythe result publication process of the parent system; a resultverification process for verifying the result received by the resultreception process; and the computer processes that are performed by thecomputer of each of the second plurality of subsystems comprises: asetting reception process for receiving the initial setting informationwhich has been made public by the setting publication process of theparent system; a random number generation process for generating arandom number; a response generation process for generating a responseby using the random number generated by the random number generationprocess; a response sealing process for sealing the response generatedby the response generation process; a sealed response sending processfor sending the sealed response generated by the response sealingprocess; a contact-signal reception process for receiving the sealedresponse which has been made public by the contact-signal publicationprocess of the parent system; a contact-signal verification process forverifying the sealed response received by the contact-signal receptionprocess; a broken-seal response sending process for sending thebroken-seal response since the contact-signal verification process canverify the sealed response; a result reception process for receiving theresult which has been made public by the result publication process ofthe parent system; and a result verification process for verifying theresult received by the result reception process.
 16. The computer usablemedium according to one of claims 13, 14 and 15, wherein the initialvalue sealing process of the parent system uses a hash function to sealthe initial value; and the result calculation process of the parentsystem uses a hash function to obtain the lottery result.
 17. Thecomputer usable medium according to one of claims 14, 15 and 16, whereinthe response sealing process of each of the child subsystems uses a hashfunction to seal the response.